"The Messenger of Allah went to the toilet and said: 'Bring me three stones.' So I brought him two stones and a piece of dung. He took the two stones and threw the dung away, saying: 'It is impure.'" (Using translation from Ibn Mājah 314)
أَمَرَنِي رَسُولُ اللهِ ﷺ أَنْ آتِيَهُ بِثَلَاثَةِ أَحْجَارٍ فَأَتَيْتُهُ بِحَجَرَيْنِ وَرَوْثَةٍ فَأَخَذَ الْحَجَرَيْنِ وَأَلْقَى الرَّوْثَةَ وَقَالَ ايتِنِي بِحَجَرٍ